Process for refining hydrocarbon materials



Patented June 26, 1934 UNITED STATES PATENT OFF! E William Alvah Smith,Hamburg, N. Y.

No Drawing. Application November 22, 1930, Serial No. 497.612

15 Claims. (CL 19H.)

This invention relates to improvements in methods of removing fromhydrocarbon mixtures certain obiectional ingredients, such as sulphurcompounds, gummy constituents and the like.

It has heretofore been common practice to treat hydrocarbon mixtureswith various metals and metallic salts for the purpose of formingchemical compounds with certain materials to be removed from thesemixtures, and it has also been customary to use materials havingadsorptive properties for removing certain ingredients from thesemixtures. For example, fuller's earth has been used to remove certainingredients because of the adsorptive properties of fuller's earth, but

id iuller's earth as well as other similar adsorptives has certainobjections, such for example as increasing the formation of gummyconstituents of the hydrocarbon mixture after treatment, and when usedin connection with motor fuels, these 20 adsorptives destroy some of theanti-knock properties and in some cases materially increase the endpoint of the liquid.

The objects of this invention are to provide an improved process forremoving from hydro- 2 carbon mixtures certain objectionable gums andgum forming materials; also to provide a process of this kind inaccordance with which the hydrocarbon mixtures are treated with asilicate or silicates of copper; also to provide a proces of this kindin which a simultaneous removal of sulphur compounds and gummyconstituents rrom hydrocarbon mixtures is effected; also to improveprocesses of this kind in other respects hereinafter specified, tosupply a process for removal of gummy materials after sulphur isremoved.

In my co-pending application Serial No. 393,585, flied September 18,1929, of which this application is a continuation in part, I prescribedthe use of copper silicate for the removal of sulphur from petroleumdistillates. In accordance with my present invention, copper silicatesare employed not only for removing the sulphur compounds from petroleumdistillates, but also for removing gummy or gum forming ingredients fromany hydrocarbon mixtures, whether the same are ingaseous, vaporous.or'liquid form, and if desired, thccopper silicate-maybe used forsimultaneously removing sulphur compoimds and gummy material from suchmixtures.

Themannerofcarryingoutthismethodmayvaryaccordingtothemixtureswhicharebeing treated, and in with the resultsdesired. In accordance with mymethod, it isnecessarytosecurethecontactofthemixturetobe purified with the coppersilicate. If the hydrocarbon material to be treated is in gaseous orvaporous state, the material may be forced through filtration bedsformed of copper silicate or by otherwise intimately mixing the finelydivided material with vaporized or gasified hydrocarbon. When passingdry gas through this material, it is often desirable to mix the granularor pulverized copper silicate with kerosene or some other convenientliquid to retain the sillcate in the treating chamber. In treatinghydrocarbon liquids the copper silicate may be added to the liquid,which is then circulated or agitated to secure an intimate mixing of thecopper silicate with the liquid. If desired. the liquid may be treatedin steps by first subjecting the liquid to a partial treatment by acomparatively small quantity of copper silicate, and then removing thecopper silicate and adding additional fresh copper silicate to theliquid. If desired, the copper silicate can be used in conjunction withother treating agents. For example cracked gasoline or pressuredistillate may be treated with sodium hydroxide, either liquid orgranular, copper hydroxide or other alkaline compound for removal ofhydrogen sulfide and the conversion of mercaptans to disuliides. Thistreatment may be followed efiectively by contacting the pressuredistillate with copper silicate which removes additional sulfurcompounds, gums and gum forming constituents.

The temperature of the material under treatment may be varied asdesired, depending upon the results desired and the material undertreatment. Ordinary temperatures are of course most convenient but insome cases treatment at elevated temperatures and pressures isdesirable. For example, in the manufacture of rubber solvents from Limacrude it is advantageous to treat the solvent with copper silicate atthe refluxing temperature of the solvent, to produce a noncornosiveproduct. In the case of cracked gasoline distillate it is oftendesirable to carry out the treatment at temperatures below F. to producewater white products.

I have found that various copper silicate compounds may be effectivelyemployed for this pur In some cases copper meta silicate can be veryeffectively used, but I have found that in most cases copper silicatescontaining a greater amount of silica than the meta silicate are moreeffective in the removal of gums. Not only do the copper silicatesremove gums actually found in the hydrocarbon mixtures, but also somegum forming materials in these mixtures, as well as sulphur compounds.While I do not know just what reactions take place in the carrying outof my process, it is very likely that at least a part, if not all, ofthe sulphur compounds are removed by reacting chemically with the coppersilicate to form sulphur compounds or complexes insoluble in thehydrocarbon mixture. The gums appear to be removed from mixture, becauseof the adsorbent properties of copper silicate, since in many cases gumsmay be removed from the copper silicate after treatment of a hydrocarbonmixture by the copper silicate by merely washing the copper silicatewith a gum solvent. It is also possible that the copper silicate mayhave a polymerizing effect upon certain gum forming ma terials containedin the mixture resulting in the forming of such gums and their removalby adsorption.

After treating a hydrocarbon mixture, the copper silicate may berestored approximately to its original condition for further use in anysuitable manner; for example, by heating the copper silicate which hasbeen removed from the mixture, and thus driving off any'gummy or gumforming substances adhering to the copper silicate. The copper silicatemay alsobe revivifled by subjecting the same after removal from thehydrocarbon mixture to the action of certain organic solvents, such asmixtures of benzol, from which solvents the gums can be recovered, ifdesired. Other solvents may be used such as acetone, amyl acetate,chloroform, and carbon tetrachloride. If these methods fail tosufllcientiy revivify the copper silicate, the constituents may berecovered by oxidizing at a sufficiently high temperature to form copperoxide and silica, in which the copper oxide can be recovered bydissolving the same out with acids to form copper salts, or in any otherconvenient manner.

The most convenient manner of forming the various copper silicates is tocause a reaction between the corresponding sodium or potassium silicateswith a water solution of a water soluble copper salt, such for exampleas copper sulfate, thus forming corresponding copper silicates andsodium or potassium sulfate. Usually these materials in water solutionare gelatinous in form, and when dried sufficiently, lose their abilityto form gelatinous precipitates when remixed with water. By causing thereaction to take place in a concentrated solution, a substantiallynongclatinous precipitate is formed which can be easily dried. The driedcopper silicates are of a granular nature somewhat similar to fine sand,

and in this form are much more effective in their actionupon'dry'hydrocarbon mixtures than when in gelatinous form: and,furthermore, the removal of these copper silicates from the hydrocarbonmaterial under treatment can be easily eilected by centrifuging,precipitation, filtration, settling many other desired method whichwould occur to one skilled in the art, or, if desired, byredistillation. Because of the form of these dried copper silicates,they do not tend to pack in the presence of a hydrocarbon liquid. Thesilicates may be reduced to powder by grinding.

In localities containing natural copper silicate deposits such aschrysocolla, dioptase and planchette these may be used instead of theartificially made silicates referred to, although the latter arepreferred.

In accordance with this process, by treatment of a hydrocarbon mixturewith copper silicate, the sulphur compounds, as well as gummy materials,maybe removed in the same operation.

As in the case of other treating agents the proportion of coppersilicate to hydrocarbon material treated varies with the character andorigin of the material as, well as with the previous treatment to whichthe material has been subjected. As an example of the proportion andresults obtained from the treatment of 400 F. end point cracked gasolineproduced from gas oil derived from Refugio crude oil, the following isillustrative. The cracked distillate which had a copper dish gum of over600 mg. per 100 c. c., a sulfur content of 0.06%, and a color of 12 wastreated in two successive steps for one and one-fourth hour each-first,with 2 pounds of copper silicate (CuO to S10: ratio 1 to 4) per barrelof distillate, and, second with one and one-half pounds of the coppersilicate. The treated distillate which was "doctor sweet andnon-corrosive showed the following properties:

Gum (copper dish) 8mg.per 100 cc.

The very unusual results obtained by the treatment of hydrocarbonproducts which deposit gums, turn sour and go oil color on standing maybe attributed at least in part to the catalytic action of the coppersilicate compound in precipitating, polymerizing or otherwise removingthe gums, sulfur compounds and color compounds or the constituents ofhydrocarbon material which form such. Other copper compounds previouslytried do not have this property or give the results obtained by the useof copper silicate.

Some of the more important advantages of the process of thepresentinvention are: the simplicity and economy of treatment, the finishing ofthe treated product without raising its end point, without ,using othertreating agents or without rerunning, and in the case of gasolines thevery important advantage of not substantially lowering its anti-knockvalue.

Having describedmy invention, what is claimed as new :is:

l. A process of removing sulphur compounds,

gums, and gum forming materials from hydro carbon mixtures. whichincludes subjecting the mixtures in fluid form to the action of a coppersilicate containing more than one molecule of silica for eachmole'culeof copper.

2. A process of removing sulphur compounds, gums. and gum-formingmaterials from liquid hydrocarbon mixtures, which includes removingsulphur compounds by chemical reaction with copper silicate,polymerizing gum forming materials into gums by means of coppersilicate, and removing gums from the liquid by adsorption by said coppersilicate.

8. A process of, removing gums from hydrocarbon mixtures, which includessubjecting the mixtures in fluid condition to the actionof a cop'- persilicate, separating the copper silicate from the mixtures, and'thenseparating the gums from the coppersiiicate to .render the coppersilicate re-usable for removal of furiier gums from bydrocarbonmixtures.

4. A process-of removinggums from hydrocarbon mixtures, which includessubjecting the mixtures while in fluid condition to the action of acopper silicate, separating the copper silicatefrom-the'mixtures,dissolving the gums from the copper silicate in asolvent, and recoveriyig the ums.

5. The method of removing objectionable ingredients from hydrocarbonmixtures, including reacting upon a silicate of an alkali metal with awater soluble copper salt to form a corresponding copper silicate,drying said copper silicate, and subjecting the hydrocarbon mixtureswhile in fluid condition to contact with the dried copper silicate.

6. The process of removing objectionable ingredients, such as sulphurcompounds, gums, and gum forming materials from fluid hydrocarbonmixtures which includes subjecting such mixtures to intimate contactwith copper silicate at a temperature materially below crackingtemperatures.

'7. The process of removing sulphur compounds, gums and gum formingmaterials from fluid hydrocarbon mixtures. which includes removingsulphur compounds by chemical reaction with particles of solid coppersilicate, polymerizing gum forming materials into gums by means ofparticles of solid copper silicate, and removing the gums from themixtures by absorption by particles of said copper silicate.

8. The process of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from fluid hydrocarbonmixtures which comprises subjecting the mixtures to intimate contactwith particles of dry copper silicate.

9. The process of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from fluid hydrocarbonmixtures which comprises subjecting the mixtures to intimate contactwith particles of dry copper silicate, and at a temperature notmaterially exceeding room temperature.

10. The process of removing objectionable ingredients, such as sulphurcompounds, gums, and gum forming materials from fluid hydrocarbonmixtures which includes subjecting such mixtures to intimate contactwith a meta silicate of copper.

11. The method of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from a liquid hydrocarbonmotor fuel, without material change in the anti-knock properties of thefuel, which comprises subjecting said fuel to intimate contact withcopper silicate.

12. The method of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from a liquid hydrocarbonmotor fuel, without material change in the antiknock properties of thefuel, which comprises subjecting said fuel to intimate contact with dryparticles of copper silicate.

13. The method of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from a liquid hydrocarbonmotor fuel, without material change in the anti-knock properties of thefuel, which comprises subjecting said fuel to intimate contact withcopper silicate at temperatures materially below cracking temperatures.

14. The method of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from a liquid hydrocarbonmotor fuel, without material change in the antiknock properties of thefuel, which comprises subjecting said fuel to intimate contact withcopper silicate containing more than one molecule of silica for eachmolecule of copper.

15. The method of removing objectionable substances, such as sulphurcompounds, gums, and gum forming materials from a cracked gasolinedistillate, which consists in subjecting said distillate to intimatecontact with true copper silicate at a temperature below approximately70 F., and separting the insolubles from the liquid to produce a waterwhite distillate.

WILLIAM ALVAH SMITH.

